Bold asteroid-snatching plans to appear in NASA 2014 budget

Proposed mission would stash a rock near the Moon, and send people to visit.

Aviation Week is carrying the news that NASA's FY2014 budget will include a $100 million line item to start planning a robotic mission to snatch an asteroid and relocate it to near the Moon, where it could be studied up-close by NASA—and possibly even visited by astronauts (hat-tip to the Houston Chronicle's SciGuy blog for the news).

The idea is based on a report by the Keck Institute for Space Studies, which outlines an entire robotic mission to locate and retrieve an NEA—a Near Earth Asteroid—of about 500,000kg in mass and a diameter of about 7 meters. Such an asteroid would be a C-type or carbonaceous asteroid, and would have the consistency of "a dried mudball." The asteroid would be hauled back via a robotic probe and positioned in an orbit above the far side of the Moon at the second Earth-Moon Lagrange Point, where the vagaries of gravity and inertia would keep the asteroid in a roughly consistent location. Once positioned there, the asteroid would—at least in theory—be within the range of a manned visit.

To go out and grab the asteroid in the first place, the report recommends a probe weighing about 18,000 kg, which could be lofted into space using an existing launch vehicle (such as an Atlas V). Shifting 500,000 kg of mass with conventional rockets would require a tremendous amount of propellant to be carried along with the probe so, rather than chemical rockets, the probe would be equipped with a "~40-kW solar electric propulsion system with a specific impulse of 3,000 s."

That's an ion thruster, as the technology is more commonly known. This type of engine works not by burning propellant in a thrust chamber, but rather by using electricity generated by solar panels to accelerate charged particles away from the spacecraft. The thrust from such an engine is relatively low, but its specific impulse—a measurement of the engine's efficiency at extracting force from a given amount of fuel—is extremely high. By way of comparison to the 3,000 s figure above, the RS-25 engines used on the Space Shuttle burn liquid hydrogen and have a specific impulse of 453 seconds in a vacuum.

The probe could use various gravity assist methods to reach its candidate asteroid, depending on where the target happens to be. Most of the potential rendezvous methods include a slingshot around the Moon to give the probe a big velocity boost out of the Earth-Moon system. Once the probe has reached its asteroid target, it would enfold the asteroid in a large bag and stabilize any tumble or rotation it happens to have using xenon-powered maneuvering thrusters. Once stable, it would begin a long ion-powered trek back to the Moon. Once the probe has returned to the Moon's vicinity with its cargo, it would initiate a braking maneuver (again using the Moon's gravity to assist) and stabilize itself in high lunar orbit at the EML2 point.

Because of the low available thrust and the high amount of mass involved, the entire retrieval mission could take up to ten years, depending on the candidate asteroid's location and orbit. Once the asteroid has been installed at EML2, the report says that it would remain stable with only a tiny amount of help: "We estimate that the lunar orbit could be maintained with station-keeping on the order of 10 m/s ∆V per year." The probe would remain attached to the asteroid in order to impart this momentum, though it would not have the propellant reserves to do this for very long and would need to have its xenon supply topped off for long-term station-keeping.

So, once it's there, what do we do with it? The report outlines several science possibilities, but NASA and the current administration are focused on sending astronauts out to visit. Manned exploration of a 7-meter asteroid might seem a bit of a stretch, but the report explains thusly:

Placing a 500-t asteroid in high lunar orbit would provide a unique, meaningful, and affordable destination for astronaut crews in the next decade. This disruptive capability would have a positive impact on a wide range of the nation’s human space exploration interests. It would provide a high-value target in cislunar space that would require a human presence to take full advantage of this new resource. It would offer an affordable path to providing operational experience with astronauts working around and with a NEA that could feed forward to much longer duration human missions to larger NEAs in deep space.

There's another reason, too: rendezvous with a NEA is one of the potential objectives outlined in the Augustine report, a document commissioned by the government that attempts to give some direction to America's manned space program. The vast majority of the report's recommendations and conclusions appear to have been largely ignored; however, NEA rendezvous is mentioned as a potential way to keep the manned space program performing some meaningful work while looking for a bigger, more permanent goal:

There is a third possible path for human exploration beyond low-Earth orbit, which the Committee calls the Flexible Path. On this path, humans would visit sites never visited before and extend our knowledge of how to operate in space—while traveling greater and greater distances from Earth. Successive missions would visit lunar orbit; the Lagrange points (special points in space that are important sites for scientific observations and the future space transportation infrastructure); and near-Earth objects (asteroids and spent comets that cross the Earth’s path); and orbit around Mars....

The Flexible Path represents a different type of exploration strategy. We would learn how to live and work in space, to visit small bodies, and to work with robotic probes on the planetary surface. It would provide the public and other stakeholders with a series of interesting "firsts" to keep them engaged and supportive.

A captured asteroid would provide NASA with another destination, besides the International Space Station, that astronauts could visit using the in-development Orion spacecraft. It also will provide a way to demonstrate the heavy-lift capabilities also-in-development Space Launch System. However, adding a manned component to the mission introduces a lot of dependencies—SLS's actual development and commissioning is still not entirely a sure thing. (Detractors often refer to the rocket as the "Senate Launch System" because of the large number of design and assembly contracts being run by the aerospace companies all across the country.)

The mission as outlined comes across as more of a technology demonstration and practice run than anything else, although there is obviously the opportunity for real science in the capturing and up-close observation of an asteroid. Aviation Week cites a number of experts who discuss objectives beyond just capture and rendezvous; the mission itself could serve as a test for technology that could eventually be scaled up to avert a collision with an inbound asteroid, for example. The presence of a carbonaceous asteroid in cis-lunar space also gives private companies the opportunity to test mining techniques to extract resources from the floating rock. Success could lead to additional robotic capture-and-return missions or even remote-controlled mining missions that return not whole asteroids but rather mined ore ready to be processed.

From a cost perspective, the $100 million line expected to appear in NASA's FY2014 budget is just the start, though: the total cost of the mission would be about $2.6 billion dollars (and that excludes any costs associated with later manned visits). Much of that $2.6B is tied up in the research and planning and manufacturing, and repeat missions would be less—perhaps $1B each.

The mission could launch as early as 2017, depending on the asteroid chosen. The combined Orion/SLS system is expected to make its first manned flight in 2021.

83 Reader Comments

I wonder why a carbonaceous rock was chosen as the target. At the same mass, a smaller mostly-metal asteroid could prove an economic resource NASA could sell access to once in orbit. Flying out to harvest the metal accomplishes all the "mission experience" goals that a carbonaceous rock would.

I wonder why a carbonaceous rock was chosen as the target. At the same mass, a smaller mostly-metal asteroid could prove an economic resource NASA could sell access to once in orbit. Flying out to harvest the metal accomplishes all the "mission experience" goals that a carbonaceous rock would.

The report elaborates a bit on that, but one of the reasons is low mass and the other is potential safety in case there's any problem and the rock is misdirected toward earth. A carbonaceous asteroid won't survive re-entry and won't strike the surface anywhere.

What's the protection against accidentially slamming this into earth in the event of a mistake?

Our atmosphere.

Also, orbital mechanics. There's always the possibility of wild navigational error, but things traveling through the solar system don't tend to move in straight lines. Aiming for the moon and accidentally hitting earth isn't as easy as you might think.

I see this as the first step toward asteroid mining, which could potentially make NASA self-supporting

Before the quantity of resources you could mine from an asteroid surpass in value the quantity of resources you have to commit to get there and mine it, a lot of things have to change in technology (if not physics!)

This will be the new "Gold Rush" of the 21st Century and it is just getting started. Eventually when we make it out to the out rim of the Asteroid Belt, the real rush will begin. This is the future of space mining operations and it is awesome. I suspect wars will be fought over all the natural mineral and metal deposits that are all over the Solar System.

I see this as the first step toward asteroid mining, which could potentially make NASA self-supporting

Before the quantity of resources you could mine from an asteroid surpass in value the quantity of resources you have to commit to get there and mine it, a lot of things have to change in technology (if not physics!)

At current prices this asteroid, if it was nickel and not dirt, would be worth about $500,000. Not really worth it. If it was solid gold, then it would be worth going and getting it, although that much gold would distort the markets, but it is worth 26 billion US$ at current market price.

At current prices this asteroid, if it was nickel and not dirt, would be worth about $500,000. Not really worth it. If it was solid gold, then it would be worth going and getting it, although that much gold would distort the markets, but it is worth 26 billion US$ at current market price.

If it was pure nickel, it would be worth 8,267,500 at current prices (16535.00 per metric tonne).

However, most nickel-carrying asteroids are a mix of nickel, iron and other stuff, making it much less worth: Iron ore is only worth around 154.64 per metric tonne, nickel even less.

If it was JUST iron and nickel at, lets say 50/50, and was easy to separate it would be worth a little over $5,000,000.

(Funny thing: Iron seems to be traded as ore, nickel as pure product. Prices for nickel ore was hard to find, probably because purity is usually low and differs quite a bit)

Nevertheless, your point stand: It'll have to be a pretty damn efficient operation to turn a profit.

we really need to get more funding for this, and NASA in general. a pointless war with no redeeming qualities costs many trillions of dollars. come on, america.

It makes me sick to think where we could have accomplished by now if our space program had stayed locked at 4% of GDP. (It's been steadily whittled down over the years to it's current level -which is now only 1/10th of that.) Hell, we were supposed to be on Mars in 1983. (That's one can that'll be kicked down the road forever.)

Instead, we start programs, spend money on them -and then cancel them in mid-development because of under funding or the whims switching administrations.

The space station was one vote short of being canceled. The Curiosity Rover was also within a hair of getting axed. The Venturestar was 90% complete before it was canceled. The Shuttle flights were cancelled after being only 10-20% through their designed lifetimes. And on and on...

Why L2? Isn't that one of the unstable Lagrange Points? Wouldn't L4 or L5 where gravity does your station keeping for you make more sense?

I suspect that L4 and L5 are too far away to be easily (i.e., cheaply) reached by manned missions.

But who decides what all gets to park at L1 or L2 - or any of them, for that matter? What if the Chinese want to park a space station at L2? Does NASA get to smash them with a 7-meter asteroid? Space, the final lawless frontier?

At current prices this asteroid, if it was nickel and not dirt, would be worth about $500,000. Not really worth it. If it was solid gold, then it would be worth going and getting it, although that much gold would distort the markets, but it is worth 26 billion US$ at current market price.

If it was pure nickel, it would be worth 8,267,500 at current prices (16535.00 per metric tonne).

However, most nickel-carrying asteroids are a mix of nickel, iron and other stuff, making it much less worth: Iron ore is only worth around 154.64 per metric tonne, nickel even less.

If it was JUST iron and nickel at, lets say 50/50, and was easy to separate it would be worth a little over $5,000,000.

(Funny thing: Iron seems to be traded as ore, nickel as pure product. Prices for nickel ore was hard to find, probably because purity is usually low and differs quite a bit)

Nevertheless, your point stand: It'll have to be a pretty damn efficient operation to turn a profit.

However, if it could be refined and used in orbit to fabricate parts for things like stations, ships or satellites, the value skyrockets. Lets use a rough $1,000 per pound "launch cost" as a starting point, at 500,000kg, that comes out to a value of $1.1 billion.

Suddenly that makes a heck of a lot more sense. At least in a shorter term, I see no reason for mining asteroids to bring anything back to Earth. However...mining them to fabriate things in space, now that makes significantly more economic sense. It costs a huge amount to loft things in to just LEO, why not grab resources where the cost and energy budget are much lower and then move them to LEO (or where ever else in space you need them) and fabricate parts there???

I wonder why a carbonaceous rock was chosen as the target. At the same mass, a smaller mostly-metal asteroid could prove an economic resource NASA could sell access to once in orbit. Flying out to harvest the metal accomplishes all the "mission experience" goals that a carbonaceous rock would.

The report elaborates a bit on that, but one of the reasons is low mass and the other is potential safety in case there's any problem and the rock is misdirected toward earth. A carbonaceous asteroid won't survive re-entry and won't strike the surface anywhere.

Exactly. Let's practice with the not-as-dangerous rocks first before we move on to denser (and more lucrative?) objects.

Actually, I'd say a carbonaceous is great as it contains volatiles. Sure, all the metals and such would be great to have refined up in orbit for orbital construction (and boy do we need that!), but one of the major limits of any kind of permanent moon base is volatiles and food. If you have enough volatiles and organics, you could theoretically grow enough food to supplement.

I wonder why a carbonaceous rock was chosen as the target. At the same mass, a smaller mostly-metal asteroid could prove an economic resource NASA could sell access to once in orbit. Flying out to harvest the metal accomplishes all the "mission experience" goals that a carbonaceous rock would.

The report elaborates a bit on that, but one of the reasons is low mass and the other is potential safety in case there's any problem and the rock is misdirected toward earth. A carbonaceous asteroid won't survive re-entry and won't strike the surface anywhere.

Beyond that volatiles are worth more than metal. It might sound like a bajillion tons of platinum group metals is super booty, but the truth is the only real special thing about material in orbit is that it IS in orbit, and you would rather build stuff there out of lightweight materials, not heavy siderophile elements. No doubt metals will have SOME value, but you can make a LOT of lightweight stuff out of carbon and the volatiles are both quite precious and easily processed into a usable form.

At current prices this asteroid, if it was nickel and not dirt, would be worth about $500,000. Not really worth it. If it was solid gold, then it would be worth going and getting it, although that much gold would distort the markets, but it is worth 26 billion US$ at current market price.

If it was pure nickel, it would be worth 8,267,500 at current prices (16535.00 per metric tonne).

However, most nickel-carrying asteroids are a mix of nickel, iron and other stuff, making it much less worth: Iron ore is only worth around 154.64 per metric tonne, nickel even less.

If it was JUST iron and nickel at, lets say 50/50, and was easy to separate it would be worth a little over $5,000,000.

(Funny thing: Iron seems to be traded as ore, nickel as pure product. Prices for nickel ore was hard to find, probably because purity is usually low and differs quite a bit)

Nevertheless, your point stand: It'll have to be a pretty damn efficient operation to turn a profit.

However, if it could be refined and used in orbit to fabricate parts for things like stations, ships or satellites, the value skyrockets. Lets use a rough $1,000 per pound "launch cost" as a starting point, at 500,000kg, that comes out to a value of $1.1 billion.

Suddenly that makes a heck of a lot more sense. At least in a shorter term, I see no reason for mining asteroids to bring anything back to Earth. However...mining them to fabriate things in space, now that makes significantly more economic sense. It costs a huge amount to loft things in to just LEO, why not grab resources where the cost and energy budget are much lower and then move them to LEO (or where ever else in space you need them) and fabricate parts there???

Suddenly you're building things out of nickel-iron superalloys instead of aluminum. Though, as mentioned the volatiles would also help as you can make foam metal I-beams in space using any gas you want to increase the mass moment of interia (see F. Hadley Cocks' from Duke circa 1993 - his students flew a mission on a delayed Shuttle flight the make exactly such devices on a micro scale).

I wonder why a carbonaceous rock was chosen as the target. At the same mass, a smaller mostly-metal asteroid could prove an economic resource NASA could sell access to once in orbit. Flying out to harvest the metal accomplishes all the "mission experience" goals that a carbonaceous rock would.

The report elaborates a bit on that, but one of the reasons is low mass and the other is potential safety in case there's any problem and the rock is misdirected toward earth. A carbonaceous asteroid won't survive re-entry and won't strike the surface anywhere.

Beyond that volatiles are worth more than metal. It might sound like a bajillion tons of platinum group metals is super booty, but the truth is the only real special thing about material in orbit is that it IS in orbit, and you would rather build stuff there out of lightweight materials, not heavy siderophile elements. No doubt metals will have SOME value, but you can make a LOT of lightweight stuff out of carbon and the volatiles are both quite precious and easily processed into a usable form.

Heavy or light doesn't really matter. It's all a matter of yield strength. If I had an unlimited supply of metals or carbonaceous materials already in orbit the metals can be used to make wires, i-beams, and pressure vessel walls that would be difficult to match in terms of total performance using organics. That said, by the time this thing lands out carbon technology may get to a point that carbon nanotube and graphene structures are realistic. At that point screw the metals...

Lee Hutchinson / Lee is the Senior Reviews Editor at Ars and is responsible for the product news and reviews section. He also knows stuff about enterprise storage, security, and manned space flight. Lee is based in Houston, TX.